Multi-file upload and Commit API obey LFS filters

Updates Files::MultiService for the commits API which is in turn used by the
multi-file upload web UI

Ensures that files which should be in LFS are transformed into LFS pointers
Uses Lfs::Transformer which then links LfsObjectProjects on success

3 files changed, 55 insertions, 10 deletions

diff --git a/app/services/files/create_service.rb b/app/services/files/create_service.rb
index 675b05e8fc4..b8ae03842a3 100644
--- a/app/services/files/create_service.rb
+++ b/app/services/files/create_service.rb
@@ -1,9 +1,8 @@
 module Files
   class CreateService < Files::BaseService
     def create_commit!
-      handler = Lfs::FileTransformer.new(project, @branch_name)
-
-      handler.new_file(@file_path, @file_content) do |content_or_lfs_pointer|
+      Lfs::FileTransformer.link_lfs_objects(project, @branch_name) do |transformer|
+        content_or_lfs_pointer = transformer.new_file(@file_path, @file_content)
         create_transformed_commit(content_or_lfs_pointer)
       end
     end
diff --git a/app/services/files/multi_service.rb b/app/services/files/multi_service.rb
index a03c59f569d..bd88c46e4af 100644
--- a/app/services/files/multi_service.rb
+++ b/app/services/files/multi_service.rb
@@ -3,11 +3,32 @@ module Files
     UPDATE_FILE_ACTIONS = %w(update move delete).freeze
 
     def create_commit!
+      Lfs::FileTransformer.link_lfs_objects(project, @branch_name) do |transformer|
+        actions = actions_after_lfs_transformation(transformer, params[:actions])
+
+        commit_actions!(actions)
+      end
+    end
+
+    private
+
+    def actions_after_lfs_transformation(transformer, actions)
+      actions.map do |action|
+        if action[:action] == 'create'
+          content = transformer.new_file(action[:file_path], action[:content])
+          action[:content] = content
+        end
+
+        action
+      end
+    end
+
+    def commit_actions!(actions)
       repository.multi_action(
         current_user,
         message: @commit_message,
         branch_name: @branch_name,
-        actions: params[:actions],
+        actions: actions,
         author_email: @author_email,
         author_name: @author_name,
         start_project: @start_project,
@@ -17,8 +38,6 @@ module Files
       raise_error(e)
     end
 
-    private
-
     def validate!
       super
 
diff --git a/app/services/lfs/file_transformer.rb b/app/services/lfs/file_transformer.rb
index 030f2c6aeba..7c93659b60d 100644
--- a/app/services/lfs/file_transformer.rb
+++ b/app/services/lfs/file_transformer.rb
@@ -1,4 +1,16 @@
 module Lfs
+  # Usage: Open a `.link_lfs_objects` block, call `new_file` on the yielded object
+  #        as many times as needed. LfsObjectProject links will be saved if the
+  #        return value of the block is truthy.
+  #
+  #        Calling `new_file` will check the path to see if it should be in LFS,
+  #        save and LFS pointer of needed and return its content to be saved in
+  #        a commit. If the file isn't LFS the untransformed content is returned.
+  #
+  # Lfs::FileTransformer.link_lfs_objects(project, @branch_name) do |transformer|
+  #   content_or_lfs_pointer = transformer.new_file(file_path, file_content)
+  #   create_transformed_commit(content_or_lfs_pointer)
+  # end
   class FileTransformer
     attr_reader :project, :branch_name
 
@@ -9,26 +21,41 @@ module Lfs
       @branch_name = branch_name
     end
 
+    def self.link_lfs_objects(project, branch_name)
+      transformer = new(project, branch_name)
+      result = yield(transformer)
+      transformer.after_transform! if result
+
+      result
+    end
+
     def new_file(file_path, file_content)
       if project.lfs_enabled? && lfs_file?(file_path)
         lfs_pointer_file = Gitlab::Git::LfsPointerFile.new(file_content)
         lfs_object = create_lfs_object!(lfs_pointer_file, file_content)
-        content = lfs_pointer_file.pointer
 
-        success = yield(content)
+        on_success_actions << -> { link_lfs_object!(lfs_object) }
 
-        link_lfs_object!(lfs_object) if success
+        lfs_pointer_file.pointer
       else
-        yield(file_content)
+        file_content
       end
     end
 
+    def after_transform!
+      on_success_actions.map(&:call)
+    end
+
     private
 
     def lfs_file?(file_path)
       repository.attributes_at(branch_name, file_path)['filter'] == 'lfs'
     end
 
+    def on_success_actions
+      @on_success_actions ||= []
+    end
+
     def create_lfs_object!(lfs_pointer_file, file_content)
       LfsObject.find_or_create_by(oid: lfs_pointer_file.sha256, size: lfs_pointer_file.size) do |lfs_object|
         lfs_object.file = CarrierWaveStringFile.new(file_content)